Poor quality bar codes and damaged bar codes such as those shown in FIG. 1A and FIG. 1B are more difficult for a bar code reader to read. This results in decreased throughput at the retail point of sale. Referring to FIG. 2, an effective way to improve the ability to read such bar codes is to use an elongated laser beam 10 in the cross-sectional direction (shown up and down) of laser beam scanning motion (left to right as shown), so as to help average out spatial noise and improve the signal to noise (SNR) of laser scanning bar codes reading system.
A traditional arrangement for generating an elongated laser beam 10 is depicted in FIG. 3. In this arrangement, a Visible Laser Diode (VLD) 14 generates laser light. The VLD 14 is fitted within a yoke 18. The laser light passed through a collimator lens 22 that causes the light rays from VLD 22 to be parallel to each other. The collimated light finally passes through an aperture in a barrel 26 to cylindrical lens 30 to emerge as the elongated laser beam 10. This arrangement is discussed in greater detail in U.S. Pat. No. 8,376,233 to Horn et al., which is hereby incorporated by reference. In this arrangement, in order to get an extremely elongated laser beam, a cylindrical Lens or a cylindrical fold mirror (CFM) is used in the optical path. Unfortunately, this contributes to the part count for the assembly and also increases the difficulty of alignment of the optical system.